1. Field of the Invention
The present invention relates to a temperature setting method for a thermal processing plate, a temperature setting apparatus for a thermal processing plate, and a computer-readable storage medium.
2. Description of the Related Art
In a photolithography process in manufacturing, for example, a semiconductor device, for example, resist coating treatment of applying a resist solution onto a processing film on a wafer to form a resist film, exposure processing of exposing the resist film into a predetermined pattern, heat-processing of accelerating the chemical reaction in the resist film after exposure (post-exposure baking), and developing treatment of developing the exposed resist film are performed in sequence, so that a predetermined resist pattern is formed on the wafer by the series of photolithography processing. The wafer is then subjected to etching treatment in which a predetermined etching pattern is formed in the processing film.
For example, the heat-processing such as the aforementioned post-exposure baking is usually performed in a heat-processing unit. The heat-processing unit includes a thermal plate mounting and heating the wafer thereon. The thermal plate incorporates a heater generating heat, for example, by power feeding, and the thermal plate is adjusted to a predetermined temperature by the heat generation by the heater.
The thermal processing temperature in the above-described heat-processing greatly affects, for example, the line width of the resist pattern formed on the wafer. Hence, to strictly control the temperatures within the wafer during heating, the thermal plate of the above-described heat-processing unit is divided into a plurality of regions, and an independent heater is embedded in each of the regions to adjust the temperature for each of the regions.
It is known that if the temperature adjustment is performed at the same set temperature for all of the regions of the thermal plate, the temperatures within the wafer on the thermal plate vary due to the difference in heat resistance of the regions, resulting in variations in line width of the resist pattern. Therefore, the set temperatures of the regions of the thermal plate are temperature-corrected (temperature offset), and the temperature correction values for the regions are set to make uniform the temperatures within the wafer mounted on the thermal plate (Japanese Patent Application Laid-open No. 2001-143850).
However, even if the temperature correction values are set to uniform the temperatures within the wafer as in the prior art, actually, sufficiently uniform line widths of the resist pattern have not been formed. Hence, it is proposed that the temperature correction of the thermal plate is performed to bring the average value of the actually formed line widths of the resist pattern to a predetermined target line width value (Japanese Patent Application Laid-open No. 2006-222354).